msp430x20x2 adc10 06

Westlund // Texas Instruments Inc.

//****************************************************************************** // MSP430F20x2 Demo - ADC10, Output Internal Vref on P1.4 & ADCCLK on P1.3

//

// Description: Output ADC10 internal Vref on P1.4, toggling between two

// avaialble options, 2.5v and 1.5v ADC10OSC also output on P1.3

//

// MSP430F20x2

//

-// /|\|

XIN|-// | | |

// |RST

XOUT|-// | |

// Vref<-|A4/P1.4 P1.3| > ADC10OSC ~ 3.5MHz - 6.5MHz

//

// L Westlund

// Texas Instruments Inc

// May 2006

// Built with CCE Version: 3.2.0 and IAR Embedded Workbench Version: 3.41A

//******************************************************************************

#include "msp430x20x2.h"

void delay(void); // Software delay

void main(void)

{

WDTCTL = WDTPW + WDTHOLD; // Stop WDT

ADC10CTL1 = CONSEQ_2; // Repeat single channel

ADC10CTL0 = REFOUT + REFON + MSC + ADC10ON;

enable_interrupt(); // Enable interrupts

TACCR0 = 30; // Delay to allow Ref to settle

TACCTL0 |= CCIE; // Compare-mode interrupt

TACTL = TASSEL_2 | MC_1; // TACLK = SMCLK, Up mode LPM0; // Wait for delay

TACCTL0 &= ~CCIE; // Disable timer Interrupt

disable_interrupt();

ADC10AE0 |= 0x10; // P1.4 ADC option select

P1DIR |= 0x08; // Set P1.3 output direction

P1SEL |= 0x08; // Set P1.3 option select

for (;;)

{

ADC10CTL0 &= ~ENC; // ADC10 disable

ADC10CTL0 ^= REF2_5V; // Toggle Vref 1.5/2.5V

ADC10CTL0 |= ENC + ADC10SC; // Sampling and conversion start delay();

}

}

void delay(void)

{

volatile unsigned long i;

for (i = 0x7FFFF; i > 0; i );

}

#pragma vector=TIMERA0_VECTOR

interrupt void ta0_isr(void)

{

TACTL = 0;

LPM0_EXIT; // Exit LPM0 on return }